Heat exchange apparatus

ABSTRACT

Heat exchange apparatus for use with an atomic reactor the core of which is cooled by a primary stream of liquid metal circulated through it. The primary stream is passed through an outer container to an inner one and is heat exchanged with a secondary liquid metal circulated through a tube-type heat exchanger housed within the inner container. An atmosphere of gas lies on top of the primary liquid surface in the outer container. The problem of vortex formation on the surface of the primary liquid is avoided by providing a series of baffles in the outer container over which the primary liquid flows in a sinuous manner.

United States Patent [72] Inventors Charles M. B. Russell Wolverton; John J. Kelly, Hornchurch, both of England [211 App]. No. 764,848 [22] Filed Oct. 3, 1968 [45] Patented Oct. 5, 1971 [7 3] Assignee The Lummus Company Bloomfield, NJ. [32] Priority Oct. 5, 1967 [3 3] Great Britain [3 1 45556/67 [54] HEAT EXCHANGE APPARATUS 7 Claims, 3 Drawing Figs.

[521 11.8. C1 165/74 [51] Int.Cl.............. F28d 3/02 [50] Field of Search 176/6 1 62;

[56] References Cited UNITED STATES PATENTS 2,491,618 12/ 1949 Luetzelschwab 165/42 X 3,434,807 3/1969 lbing et a1. 165/159 FOREIGN PATENTS 1,229,647 3/1960 France i. 165/155 Primary Examiner-Martin P. Schwadron Assistant Examiner-Theophil W. Streule Attameys- Richard J. Holton, Kevin B. Clarke and Joel 0.

Ackerman ABSTRACT: Heat exchange apparatus for use with an atomic reactor the core of which is cooled by a primary stream of liquid metal circulated through it. The primary stream is passed through an outer container to an inner one and is heat exchanged with a secondary liquid metal circulated through a tube-type heat exchanger housed within the inner container. An atmosphere of gas lies on top of the primary liquid surface in the outer container. The problem of vortex formation on the surface of the primary liquid is avoided by providing a series of bafiles in the outer container over which the primary liquid flows in a sinuous manner.

PATENT EU mm s l97l SHYET 1 [IF 3 INVENTORS Charles M. 8. Russell BY John J. Kelly ATTORNEY PATENTEU [JCT 5 I97! SHEET 2 OF 3 INVENTORS Charles M. ussell John J.

PATENIEU mm 5 I97:

SHEET 3 [IF 3 INVENTORS Charles M. B. Russell Fig. 5.

I ATTORNEY HEAT EXCHANGE APPARATUS This invention relates to heat exchange apparatus and, in particular, to apparatus for heat exchanging two liquids. More particularly, this invention relates to heat exchange apparatus for use with an atomic reactor the core of which is cooled by a primary liquid metal circulated through the core. In such apparatus the primary liquid usually flows from and to an outer container surrounding an inner container housing a tube-type heat exchanger through which a secondary liquid metal is circulated and an atmosphere of gas, for example of argon, lies on the surface of the primary liquid in the outer tank. This arrangement leads to the formation of a vortex at the surface of the primary liquid in the outer container with the result that undesirable gas bubbles tend to form on the tubes of the heat exchanger resulting in differential heating of the tubes which may lead to deformation thereof or to weakening or destruction of the joints between the tubes and the headers therefor. One method which has been used to avoid this problem is to reverse the relative positions of the two streams, that is, to circulate the primary liquid stream through the tubes of the heat exchanger and pass the secondary liquid over the outside of the tubes. This system, however, possesses the disadvantage of being somewhat expensive since the primary liquid must be piped to the exchanger channel and apparatus must be provided for this purpose.

Accordingly, it is an objective of this invention to provide means for preventing the formation of such a vortex. It is a further objective of this invention to provide means for preventing the formation of gas bubbles on the tubes of the heat exchanger. It is a still further objective to provide such means without substantially increasing the cost of the apparatus.

According to the invention there is provided heat exchange apparatus for use with an atomic reactor the core of which is cooled by a primary liquid metal circulated through the core, wherein the primary liquid flows from and to an outer container surrounding an inner container housing a tube-type heat exchanger through which a secondary liquid metal is circulated, and wherein baffle means provided in the outer container at a position below the normal level of primary liquid in the outer container are arranged to cause a sinuous flow of primary liquid from the outer to the inner container to avoid the formation of a vortex at the surface of the primary liquid in the outer container and the formation of gas bubbles on the tubes of the heat exchanger.

In one embodiment of the invention the baffle means comprises a substantially horizontal plate surrounding the heat exchanger at said position below the normal level of the primary liquid in the outer container, an outer annular baffle extending from said plate downwards towards the bottom of the outer container and having its lower end spaced from said bottom, and an inner annular baffle extending upwards from said bottom, said inner baffle being located between the outer baffle and the heat exchanger, having its upper end spaced from said plate, and extending upwards past the opening formed between said bottom and the lower end of the outer baffle. The said plate may consist of a first portion surrounding the heat exchanger and a second portion which is annular and spaced radially from the first portion, and resilient steel sealing element can be provided to seal the space between said first and second portions.

The reactor may be spaced from the containers and be included in a closed circuit through which primary liquid is pumped to and from the outer container and through the reactor core.

In order that the invention may be clearly understood one embodiment thereof will now be described, by way of exam pie, with reference to the accompanying diagrammatic drawings, in which:

FIG. I is a diagrammatic elevation of apparatus according to the invention,

FIG. 2 is a section on line "-11, FIG. 1, some parts being omitted for clarity, and

FIG. 3 is a section to an enlarged scale of a part of FIG. 1.

Referring to the drawings, the heat exchange apparatus is intended for use with an atomic reactor, not shown, the core of which is cooled by a primary liquid metal, for example liquid sodium, which is circulated through the core. The primary liquid flows from and to an outer container or tank I, spaced from the reactor, which surrounds an inner container or tank 2 housing a tube-type heat exchanger 3 of any suitable kind and through which a secondary liquid metal, for example liquid sodium, is circulated by a pump, not shown. The secondary liquid flows into a central tube 4 of the heat exchanger and into a lower header 5 from which it passes upwards through the heat exchanger tubes 6, FIG. 3, to an upper header 7 and thence out through outlet pipes 8, which connect to steam generators or the like.

The primary liquid is circulated by a pump, not shown but housed in the space 9, FIGS. 1 and 2, of a main tank 10 and on delivery to the container 1, through pipe 21, flows therefrom into the inner container 2 in which it is in heat exchange relation with the tubes 6, and out of container 2 through outlet 11 into the lower part of the main tank 10 for return to the core of the reactor. The outlet 1 I may be formed by the container 2 having an open bottom, or may be an outlet attached to the bottom of container 2. h

To avoid the formation of a vortex at the surface 12 of the primary liquid in container 1 and the formation of gas bubbles on the sides of the tubes 6, bafile means are provided in the outer container 1 at a position below the normal level 12 of the primary liquid in the outer container and the baffle means are arranged to cause a sinuous flow of the primary liquid from the outer to the inner container. As shown in the drawings, see particularly FIG. 3, the baffle means comprises a substantially horizontal plate 13 surrounding the heat exchanger 3 at said position below the normal level 12 of the primary liquid in the outer container 1, an outer annular baffle 14 extending from the plate 13 downwards towards the bottom 15 of the outer container 1, and an inner annular baffle 16 which extends upwards from the bottom 15. The outer baffle 14 has its lower end 17 spaced from the bottom 15 and the inner baffle has its upper end 18 spaced from the plate 13. The inner baffle 16 is also located between the outer baffle 14 and the heat exchanger 3 and extends upwards past the opening 19 formed between the bottom 15 and the lower end 17 of the outer baffle 14.

As shown in FIG. 3, the plate 13 consists of a first portion 13a surrounding the heat exchanger 3 and a second portion 13b which is annular, is spaced radially from the first portion 13a, and is supported by the tank. A resilient steel sealing element 20 seals the space between the first and second portions 13a, 13b and permits the entire heat exchange unit to be removed from the reactor tank leaving the plate portion 13b and baffle 14 in position.

Thus primary liquid flowing from the outer container 1 to the inner container 2 passes downwards beneath the lower end 17 of baffle 14, upwards and over the upper end 18 of baffle I6, and downwards into the inner container 2.

As shown in FIG. 2 the apparatus includes two tube-type heat exchangers 3 each of which is housed in an inner container 2 to receive primary liquid from the outer container I. However, this is not intended to so limit the apparatus, which may include one or more heat exchangers as desired. Although in the foregoing description the heat exchange apparatus has been described as housed in a main tank 10 spaced from the reactor, the tank 10 may, if desired also house the core of the reactor and the pump for circulating the primary liquid through the closed circuit which includes the core.

What is claimed is:

1. Apparatus for heat exchanging two liquids comprising: a storage tank containing a first liquid, a vertically disposed heat exchange apparatus located in said storage tank comprising:

An outer container having inlet means to introduce first liquid thereinto,

An inner container at least partially enclosed within said outer container, and in fluid flow communication therewith, and having inlet means located in its upper portion for introducing said first liquid and outlet means located in its lower portion for discharging said first liquid,

Conduit means at least partially enclosed within said inner container for passing a second liquid in indirect heat exchange relationship with said first liquid in said inner container, disposed so as to maintain said second liquid in complete isolation from direct contact with said first liquid, and

Baffle means located within said outer container for imparting a sinuous horizontal flow to said first liquid comprismg:

a substantially horizontal member located in the outer container below the level of the surface of said first liquid;

an outer bafile connected to and extending downward from said substantially horizontal member toward the bottom of said outer container;

an inner baffle connected to and extending upward from the bottom of said outer container toward said substantially horizontal member;

the lower end of said outer baffle being spaced from the bottom of said outer container; and

the upper end of said inner bafi'le being spaced from said substantially horizontal member.

2. Apparatus according to claim 1 wherein the outer container, inner container, and conduit means are disposed concentrically.

3. Apparatus according to claim 1 wherein the inner and outer containers are substantially cylindrical in fonn, the substantially horizontal member is substantially circular in form, and the inner and outer baffles are substantially annular in form.

4. Apparatus for heat exchanging two liquids, for use in connection with an atomic reactor comprising: a storage tank containing a first liquid, a vertically disposed heat exchange apparatus located in said storage tank comprising: a storage tank containing a first liquid, a vertically disposed heat exchange apparatus located in said storage tank comprising:

a substantially cylindrical outer container having inlet means to introduce a first liquid thereinto;

a substantially cylindrical inner container at least partially enclosed within said outer container, and in fluid flow communication therewith, and having inlet means located in its upper portion for introducing said first liquid and outlet means located in its lower portion for discharging said first liquid;

conduit means for passing a second liquid in indirect heat exchange relationship with said first liquid in said inner container at least partially enclosed within said inner container, disposed so as to maintain said second liquid in complete isolation from direct contact with said first liquid; and

baffle means located within said outer container for imparting a sinuous horizontal flow to said first liquid, comprising:

a substantially horizontal circular member located in the outer container below the level of the surface of the first liquid;

a substantially annular outer bafile connected to and extending downward from said substantially horizon tal member toward the bottom of the outer container;

a substantially annular inner baffle connected to and extending upward from the bottom of the outer container toward said substantially horizontal member;

the lower end of said outer baffle being spaced from the bottom of the outer container, and the upper end of said inner baffle being spaced from said substantially horizontal member.

5. Apparatus according to claim 4 wherein the conduit means comprises: I t

Inlet means for introducing the second liquid into said conduit means; a first conduit connected to said inlet means; collecting means connected to said first conduit; a second conduit connected to said collecting means and arranged in parallel relationship with said first conduit; and outlet means connected to said second conduit. 6. Apparatus according to claim 5 wherein said conduit means is removably connected to the inner container.

7. Apparatus according to claim 4 wherein the outer container, inner container, and conduit means are disposed concentrically. 

1. Apparatus for heat exchanging two liquids comprising: a storage tank containing a first liquid, a vertically disposed heat exchange apparatus located in said storage tank comprising: An outer container having inlet means to introduce first liquid thereinto, An inner container at least partially enclosed within said outer container, and in fluid flow communication therewith, and having inlet means located in its upper portion for introducing said first liquid and outlet means located in its lower portion for discharging said first liquid, Conduit means at least partially enclosed within said inner container for passing a second liquid in indirect heat exchange relationship with said first liquid in said inner container, disposed so as to maintain said second liquid in complete isolation from direct contact with said first liquid, and Baffle means located within said outer container for imparting a sinuous horizontal flow to said first liquid comprising: a substantially horizontal member located in the outer container below the level of the surface of said first liquid; an outer baffle connected to and extending downward from said substantially horizontal member toward the bottom of said outer container; an inner baffle connected to and extending upward from the bottom of said outer container toward said substantially horizontal member; the lower end of said outer baffle being spaced from the bottom of said outer container; and the upper end of said inner baffle being spaced from said substantially horizontal member.
 2. Apparatus according to claim 1 wherein the outer container, inner container, and conduit means are disposed concentrically.
 3. Apparatus according to claim 1 wherein the inner and outer containers are substantially cylindrical in form, the substantially horizontal member is substantially circular in form, and the inner and outer baffles are substantially annular in form.
 4. Apparatus for heat exchanging two liquids, for use in connection with an atomic reactor comprising: a storage tank containing a first liquid, a vertically disposed heat exchange apparatus located in said storage tank comprising: a storage tank containing a first liquid, a vertically disposed heat exchange apparatus located in said storage tank comprising: a substantially cylindrical outer container having inlet means to introduce a first liquid thereinto; a substantially cylindrical inner container at least partially enclosed within said outer container, and in fluid flow communication therewith, and having inlet means located in its upper portion for introducing said first liquid and outlet means located in its lower portion for discharging said first liquid; conduit means for passing a second liquid in indirect heat exchange relationshiP with said first liquid in said inner container at least partially enclosed within said inner container, disposed so as to maintain said second liquid in complete isolation from direct contact with said first liquid; and baffle means located within said outer container for imparting a sinuous horizontal flow to said first liquid, comprising: a substantially horizontal circular member located in the outer container below the level of the surface of the first liquid; a substantially annular outer baffle connected to and extending downward from said substantially horizontal member toward the bottom of the outer container; a substantially annular inner baffle connected to and extending upward from the bottom of the outer container toward said substantially horizontal member; the lower end of said outer baffle being spaced from the bottom of the outer container, and the upper end of said inner baffle being spaced from said substantially horizontal member.
 5. Apparatus according to claim 4 wherein the conduit means comprises: inlet means for introducing the second liquid into said conduit means; a first conduit connected to said inlet means; collecting means connected to said first conduit; a second conduit connected to said collecting means and arranged in parallel relationship with said first conduit; and outlet means connected to said second conduit.
 6. Apparatus according to claim 5 wherein said conduit means is removably connected to the inner container.
 7. Apparatus according to claim 4 wherein the outer container, inner container, and conduit means are disposed concentrically. 